The world will forever associate two names with leprosy, aka Hansen's disease: Norwegian physician Gerhard Hansen, who in 1873 discovered the bacterium that causes it; and Jacinto Convit, who created a new vaccine for the slow-acting, disfiguring and deadly disease by combining a known tuberculosis treatment with an armadillo bacterium in 1987 [sources: BBC; Encyclopaedia Britannica; Chinea; Yandell].

But Convit, who was born in Caracas, Venezuela, and died there a century later, extended his hand beyond the confines of the lab or doctor's office. Moved after encountering the disease's poor and stigmatized victims during medical school, he soon dedicated himself to helping treat them and to combating the social stigma under which they lived [sources: BBC; Chinea].

Convit also developed a vaccination against leishmaniasis, a protozoal skin disease linked to poverty and malnutrition. It is transmitted by sand fly bites [source: BBC; Encyclopaedia Britannica; Chinea].

Convit’s vaccines for leprosy and leishmaniasis are no longer in use, and the search continues for universally effective and acceptable vaccines for both diseases.

During his 75-year career, he received several honors, including Spain's Prince of Asturias Award and France's Legion of Honor. Venezuela nominated him for a Nobel Prize in 1988, but he did not win. When asked if he regretted not winning the Nobel, Convit reportedly replied that his great regret was not curing cancer [sources: BBC; Chinea; Nobel Prize].